But one of the most important lessons we took away from the bridge collapse isn’t technical. It has to do with the designer.
According to Eldridge, “eastern consulting engineers” petitioned the PWA and the Reconstruction Finance Corporation (RFC) to build the bridge for less, about which Eldridge meant the renowned New York bridge engineer Leon Moisseiff, designer and consultant engineer of the Golden Gate Bridge. Moisseiff proposed shallower supports—girders 8 feet (2.4 m) deep. His approach meant a slimmer, more elegant design and reduced construction costs compared to the Highway Department design. Moisseiff’s design won out, inasmuch as the other proposal was considered to be too expensive. On June 23, 1938, the PWA approved nearly $6 million for the Tacoma Narrows Bridge. Another $1.6 million was to be collected from tolls to cover the total $8 million cost.
There was plenty of warning from many people in the civil engineering community who didn’t think this design would work. But these warnings were dismissed. After all, this was designed by the guy who designed the Golden Gate Bridge! With credentials like that, how could he possibly be wrong? And who are you, without those credentials, to question him? The pointy-haired bosses and bean counters won out. Predictably, their victory was temporary. Incidentally, some people refer to this as one kind of halo effect: a person’s past accomplishments give others undue confidence in his performance at a different job, whether or not he’s actually doing it well. It’s a nasty little problem, and it’s a really common root cause of project failure, especially on software projects.
Lesson to learn from this disaster:
When you look at the various root causes—problematic design, cocky designer, improper materials—one thing is pretty clear. The Tacoma Narrows Bridge was a failure before the first yard of concrete was poured. Failure was designed into the blueprints and materials, and even the most perfect construction would fail if it used them.
QUESTION: What lessons have you learned from this disaster that you can apply in Software Engineering? (post your answer as comment in this page before September 18, 2009)
source: http://www.stellman-greene.com/2009/07/24/taking-stock-of-a-failed-project/
14 comments:
September 12, 2009 at 8:16 AM
when designing safety critical systems like bridges, testing is paramount. This means not just theoretical analysis but also actual trials and tests of the system prior to final implementation. A particular risk can be the adoption of new fads without a solid basis of experience, and software engineers like bridge builders need to be cautious when going beyond their existing experience, particularly when lives are at stake. It should be noted that more conservative engineers had repeatedly suggested a wider, less flexible design that might well have not failed.
Finally, it is clear that the cheapest option can turn out to be the most expensive,
adnan :)
September 12, 2009 at 11:12 PM
Cause of the failure is structure engineering becuase the wind pumps in more energy than the flexing of the structure can dissipate and finally drives the bridge toward failure due to excessive deflection and stress.
September 13, 2009 at 12:29 AM
Please don't forget to write your name after your comment.One more thing, please use your own words.thanks!
September 13, 2009 at 9:00 AM
September 13, 2009 at 1:26 PM
As we all know the most important step in making any project is fulfilling its requirements, any lacks in the requirement might cause any project to fail whether its civil , software, bio or chemicals projects.
Now, in this project the engineer did not match the requirement and wanted the cheapest solution, (which actually has cost more than it would save). then even in the process phase they dint really care about it, all they cared about was the money.
same with any software if you have any lack in the requirements you would face a really difficult situation delivering it.
You can also see a lack in requirements lead to the faliure of the following link [http://www.stellman-greene.com/blog/wp-content/uploads/2009/07/oops.png] NO STRUCTURE!!
even applying more requierements than needed would make the project a failure like what happened in Abu-Hail month were half of the building collapsed (as some say because of access features and materials they applied to it).
I think thats why the whole requirements should be stated before anything else in a project, because a failure in the requirements is a failure of the project
Mehdi
071319
September 13, 2009 at 8:02 PM
mam u nvr told in class tht wrote in ur own words........u just wrote tht after my comment...so nxt tim we will try to write in our own words........:P xd
September 13, 2009 at 8:13 PM
Conversation between a software engineer and his wife
Husband - hey dear, I am logged in.
Wife - would you like to have some snacks?
Husband - hard disk full.
Wife - have you brought the saree.
Husband - Bad command or file name.
Wife - but I told you about it in morning
Husband - erroneous syntax, abort, retry, cancel.
Wife - hae bhagwan !forget it where's your salary.
Husband - file in use, read only, try after some time.
Wife - at least give me your credit card,
i can do some shopping.
Husband - sharing violation, access denied.
Wife - i made a mistake in marrying you.
Husband - data type mismatch.
Wife - you are useless.
Husband - by default.
Wife - what is my value in your life?
Husband - unknown virus detected.
Wife - do you love me or your computer?
Husband - Too many parameters.
Wife - i will go to my dad�s house.
Husband - program performed illegal operation, it will
Close.
Wife - I will leave you forever.
Husband - close all programs and log out for another User.
Wife - it is worthless talking to you.
Husband - shut down the computer.
Wife - I am going
Husband - Its now safe to turn off your computer
September 14, 2009 at 3:33 AM
The main problem of this particular birdge was the design. the developers should never depend on the design so much that they make the actual project without examining it or testing it.they dint thougt that parctically how narrow a bridge can be and that resulted in the disater.
from software engenerring point of view if we see...if the base of any project ie any program etc, is not firm the whole software is going to fall or the software is not going to work according to the requirnment.
moreover each step should be coverd and paid attention to....never skip any step of the SDLC.
sahar qureshi
061306
September 15, 2009 at 10:15 AM
:-)
The problem of that bridge is mainly due to the not understand the actuall requirements of the project.So due to the unable to understand the requirements then other phase of engineering which is designing the engineer would mainly faces the problem in it and that is the imp phase.And the every project shows his final output by both of these stepts.
And also engineer have to be laser focused on just what the customer facing benefits of product.
So to over come the disasters like this in future engineers have to be consider two phases which were:
1.Projects Life Cycle
2.Role Of Softsware Engineering
Moreover there are aroundly 9 steps of Project Life Cycle & 8 Steps of Software Engineering which were help the engineer to build any project.
CHOUDHARY HASHAM AHMED GONDAL
Reg # 081209
September 15, 2009 at 10:22 AM
HAHAHAHA
HEHEHEHE
HOHOHOHO
Three men were on a deserted island and wanted to get back. Then a genies bottle washed up on the shore so they of course rubbed it, then the genie appeared.
The first man wished that he was back home with his wife and family, and suddenly he was back home with his wife and family.
Then the second man also wanted to be home with his wife and his family, and suddenly he was also back home with his wife and family.
Then the third man said "Oh I'm lonely now i wish my mates were back here".
And suddenly they were all back on the island!
Aooe Hasna Mana Hai............
September 17, 2009 at 1:11 PM
We should learn from this disaster how a design should be worked out as well as not only famous people should be given the first priority to work on such projects, instead one should look for those sort of people who completely understand the environment in which the project should be constructed, i.e those who experience in building high-way bridges.
This could have not taken place if the requirements for the design were completely understood and implemented, and if it would have been reviewed by one or more experts in the same field. AS it is important to understand the problems or the perspective of the experts in the earlier stages of the project, so as to overcome this sort of a huge problem.
When building projects we should consider each phase of the SDLC and make sure that each step is fully understood and completed before moving onto the next step.
So we should focus more on carefully carrying out each step of the SDLC and as well as the quality of the project rather than the price, when building such huge projects.
Syeda Mehnoor Rafaie
061308
September 18, 2009 at 7:11 AM
The challenge in software engineering is to deliver high-quality software on time to customers. Project management and estimating project cost and schedule accurately are among the major software engineering challenges. Risk management is a key part of project management. and the objective is to identify potential risks to the project at initiation, determine the probability of the risks occurring and to assess its impact if it materializes, then to eliminate or reduce the risk and to have contingency plans in place to address the risk if it materializes, and finally to track risks throughout the project.
The software engineering field is characterized by changing requirements or the introduction of new requirements late in the software development lifecycle.
The challenges in software engineering are also faced in many other disciplines. Bridges have been constructed by engineers for several millennia and bridge building is a mature engineering activity. However, civil engineering projects occasionally fall behind schedule or suffer design flaws, for example, the infamous Tacoma Narrows bridge collapsed in 1940 owing to a design flaw. The Tacoma Narrows Bridge was known for its tendency to sway in wind- storms. The shape of the bridge was like that of an aircraft wing and under windy conditions it would generate sufficient lift to become unstable. On November 7, 1940, a large windstorm caused severe and catastrophic failure. The significance of the Tacoma bridge is derived from this collapse, the subsequent investigation by engineers, and the realization that aero-dynamical forces in suspension bridges were not sufficiently understood or addressed in the design of the bridge. New research was needed and the recommendation from the investigation was to use wind tunnel tests to aid in the design of the second Tacoma Narrows bridge. New mathematical theories of bridge design also arose from these studies.
Software engineering is a less mature field than civil engineering, and it is only in more recent times that investigations and recommendations from software projects have become part of the software development process. The study of software engineering has led to new theories and understanding of software development. This includes the use of mathematics to assist in the modeling or understanding of the behavior or properties of a proposed software system. The use of mathematics is an integral part of the engineer’s work in other engineering disciplines.
However, a good requirements process will ensure that changes to the requirements are minimized and controlled, and the requirements process may include prototyping or joint user reviews to ensure that they match the needs of the customer.
The implementation of the requirements involves design, coding, and testing activities. Challenges to be faced include the technical activities of the project, communication of changes to the project learn, building quality into the software product, verifying that the software is correct and corresponds to the requirements, ensuring that the project is delivered on time, and, where appropriate. taking corrective action to recover if the project is behind schedule.
Zeeshan Munir
071305
September 18, 2009 at 9:33 AM
The initial budget proposed for Tacoma Bridge by Clark Eldrige was $11 million, whilst Leon Moisseiff, the designer and consultant engineer of golden gate bridge petitioned to construct the bridge at the cost $6 million, it was obviously next to impossible to built such a bridge with such low funds eventually resulting in poor quality construction material. Therefore, we can conclude that wrong verdicts can lead to wrong reprecussions; besides the master of the masterpiece yet proved himself to be overconfident.
Shahbaz Khan
051206
September 23, 2009 at 5:27 AM
aways follow the proper routes, if u hav done smthin before den dont try to think the things simpler nxt tym.... or ther will end like tacoma bridge
Mohsin
081201
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